How does one buy the right cam for their engine? I need to know how to buy my roller

[Nasty Wendy]

I need guidance. I am really close to completing my Stage 2 engine and I need to pick out a cam. I know that doing this properly involves all sorts of 'Black Magic'. I know that my goals will play into the selection but what engine specs are needed to really hit the nail on the head?

The car will be street driven so it will have to be fun in the lower rpm ranges. It will go to the track and I intend to make old church ladies cuss. The equipment is full race ported Champion GN1 heads (not Rs). Champion oncenter intake - gasket match porting. 6.5" Oliver Rods and Wiseco Pistons. I'll have to cc the dish of the piston or call Wiseco because I don't remember what the dish is on these. It is an On Center 153. Obviously the cc on the piston will be needed as well as other piston measurements to determine the compression ratio as well as the headgasket thickness. I want to use the thinnest headgasket I can to maximize quench but I do understand that compression ratio may dictate otherwise. The total cubic inch volume of the engine is 276.12 in³. The bore and stroke is 4.040" and 3.59". I have a Vigilante 9" 7 disc lock up converter with a zero pump that I'd like to use if possible but I won't sacrifice anything to not buy a different converter however I'd like to stay with a lock up. I know that if this turns out right then eventually the 200r will bite the dust and I'll have to go to a 400. I need to know how to select the right HYDRAULIC roller cam for this application. Thanks to all who can give me some insight. The engine was machined by Duttweiler and is complete now minus frontcover/oiling/cam.

 

[SHADOWII]

You definitely started out w/a good foundation. you have the ability to choose your h/p level for your desired performance.The limiting factor will be "it will have to be fun in the lower rpm ranges." So barring c/r and converter stall values, you are looking to make your power inthe 2500-6000 rpm range? You should be good to go w/a cam in the 206/206 to 212/212 range. Torque to rpm values can come into question if it comes on too earlyand all you end up with is a tire shreader! This where the experience of guys like Bison or Otto, etc. that have eperience w/differant combo's can better advise you. I presently run a 247" w/a 212 and shift @ 6250rpm w/7.8 to 1 c/r which allows for higher boost levels, but it is kept to 23#s now.
For max power, the limiting factor would be what the rpm for the max head flow is, which creates more variables.
That is why the first question asked is "What's your goal?" performance or h/p intended. Balance of the variables is the Key! You will fall well within your limitations. Hope this helps!

 

[Cme2fly]

Are you stuck on a hydraulic roller? Sounds like a stout engine..I would look into a solid roller in a setup like yours. If your stuck on using a hydraulic lifter, look into a shimmed lifter to minimize plunger travel. If I was in your position I would have a cam ground to your engine specs.

 

[steve hughes]

If you want the right cam call Dan at DLS.

 

[Nasty Wendy]

You definitely started out w/a good foundation. you have the ability to choose your h/p level for your desired performance.The limiting factor will be "it will have to be fun in the lower rpm ranges." So barring c/r and converter stall values, you are looking to make your power inthe 2500-6000 rpm range? You should be good to go w/a cam in the 206/206 to 212/212 range. Torque to rpm values can come into question if it comes on too earlyand all you end up with is a tire shreader! This where the experience of guys like Bison or Otto, etc. that have eperience w/differant combo's can better advise you. I presently run a 247" w/a 212 and shift @ 6250rpm w/7.8 to 1 c/r which allows for higher boost levels, but it is kept to 23#s now.
For max power, the limiting factor would be what the rpm for the max head flow is, which creates more variables.
That is why the first question asked is "What's your goal?" performance or h/p intended. Balance of the variables is the Key! You will fall well within your limitations. Hope this helps!

If I'm not mistaken the 206 is the smallest cam that you can buy 'off the shelf' for these old cars. Don't the 206s and 212s work pretty good with a 231in³ engine? I would have thought that they would be on the small side for a 276in³ engine. I'd love it if I can get away with an 'off the shelf' grind.

Are you stuck on a hydraulic roller? Sounds like a stout engine..I would look into a solid roller in a setup like yours. If your stuck on using a hydraulic lifter, look into a shimmed lifter to minimize plunger travel. If I was in your position I would have a cam ground to your engine specs.

I waffled for a long time on whether to go solid or hydraulic. I've read comparisons done in SBC engines doing direct comparisons between hydraulic and solid rollers. In those comparisons the gains were so minimal that I'd have to be building a race only car that is scraping up every single last bit of power available to justify using a solid. One of the comparisons showed the Hydraulic making MORE torque and the solid making about 8 more horsepower. If a vender would have stepped up and produced a two piece valve cover to make valve lash adjustments less of a chore then I may have gone solid but its not worth the extra work for a (wink wink) 'street car'.

If you want the right cam call Dan at DLS.

Yeah I can do that but it would help me not waste his time if I already had the info he is going to need. I need to know what info is needed for someone to aid me in selecting a cam.

 

[49-blues]

im putting 224/224 roller in my 274" with a .587" lift and 1.55 T&D rockers. just keeping it under .600" for a mostly street motor.

 

[twodafloor]

I just called Mike Licht at Full Throttle = told what I had , what I was gonna do ,he made recommendation, all good.

 

[Nasty Wendy]

49, how did you select that grind? Was there any science involved?

 

[quickt]

Yeah I can do that but it would help me not waste his time if I already had the info he is going to need. I need to know what info is needed for someone to aid me in selecting a cam.

You have the info about your combo that's all that is needed. Dan will recommend and hook you up with the right cam for your combo. Much better avenue than throwing darts here looking for the magic stick.

 

[Nasty Wendy]

You have the info about your combo that's all that is needed. Dan will recommend and hook you up with the right cam for your combo. Much better avenue than throwing darts here looking for the magic stick.

Thanks Lonnie. I'll call him on monday. I thought that I'd seen where cam selection wasn't possible without knowing the flow rate of the heads at different valve lifts. If that is the case then I'll need to get that info as I don't have any flow data on the heads.

 

[bison]

To put it simply you wont be getting anywhere near the potential out of it you could with a hyd cam. If you have the non "R" heads there are only a couple springs out there that will get it done since you are limited to about 1.850 or tighter installed height with the short valves in the non R head. Doesnt leave chit for room for common double spring setups and makes it a bitch to get a good spring in there. if you go with a serious lobe. The spring retainer combo needed to run a fast ramp hyd with over about .560 lift is about another $500 not including setup time or seals/shims.You will be limited to about .560 lift and not the fastest ramps out there unless you plan on running a billet cam and a few uncommon to turbo Buick valvetrain components. Adding lift will help a lot on those heads and that larger displacement engine. You will need to run the 885 lifters and run them almost like a solid unless you run one of the typical slower ramp lower lift cams that most run and were previously suggested. You wont even come close to having the heads become a flow restriction with a hyd in there. What they flow means little here since you will never stall them with a hyd cam. A properly spec'd solid will just about always make more power and allow you to alter the valve open/close timing to better suit your application especially if it has high back pressure. Dont believe the crap you heard about SBC making more power with a hyd. Ive seen many 90* Chevys with hyd and good heads a few with solids and good heads. Its not even a close comparison. The solid cammed engine with a single plane and big port volume will crush a hyd cam combo power wise. It may not be as streetable but the amount of hp difference is huge. Be prepared to buy more than just a cam here if you are looking to make the most out of what you have. The 6.5" oliver rod/3.625" stroke is interesting. Not typical these days. If you are running a dished piston i wouldnt be worried about too much CR. Id be worried about not enough. Fwiw your vig converter wont couple the power this thing could make. For a hard running hyd you would need your converter flashing to 5500-5600 or so with the hyd grinds that would work best here. Your peak power will be below 6000rpm. With a mild solid you wouldnt have to worry much about adjusting the lash and still be able to run a lot more spring and make more power.

 

[Nasty Wendy]

To put it simply you wont be getting anywhere near the potential out of it you could with a hyd cam. If you have the non "R" heads there are only a couple springs out there that will get it done since you are limited to about 1.850 or tighter installed height with the short valves in the non R head. Doesnt leave chit for room for common double spring setups and makes it a bitch to get a good spring in there. if you go with a serious lobe. The spring retainer combo needed to run a fast ramp hyd with over about .560 lift is about another $500 not including setup time or seals/shims.You will be limited to about .560 lift and not the fastest ramps out there unless you plan on running a billet cam and a few uncommon to turbo Buick valvetrain components. Adding lift will help a lot on those heads and that larger displacement engine. You will need to run the 885 lifters and run them almost like a solid unless you run one of the typical slower ramp lower lift cams that most run and were previously suggested. You wont even come close to having the heads become a flow restriction with a hyd in there. What they flow means little here since you will never stall them with a hyd cam. A properly spec'd solid will just about always make more power and allow you to alter the valve open/close timing to better suit your application especially if it has high back pressure. Dont believe the crap you heard about SBC making more power with a hyd. Ive seen many 90* Chevys with hyd and good heads a few with solids and good heads. Its not even a close comparison. The solid cammed engine with a single plane and big port volume will crush a hyd cam combo power wise. It may not be as streetable but the amount of hp difference is huge. Be prepared to buy more than just a cam here if you are looking to make the most out of what you have. The 6.5" oliver rod/3.625" stroke is interesting. Not typical these days. If you are running a dished piston i wouldnt be worried about too much CR. Id be worried about not enough. Fwiw your vig converter wont couple the power this thing could make. For a hard running hyd you would need your converter flashing to 5500-5600 or so with the hyd grinds that would work best here. Your peak power will be below 6000rpm. With a mild solid you wouldnt have to worry much about adjusting the lash and still be able to run a lot more spring and make more power.

6.5" rod with 3.59" stroke.

At one point I had convinced myself to run a solid and go with the 'R' heads. You can blame Jason White for changing my mind. Since he has proven that a 109 can go 9 Ohs or 9 Teens in TSM trim with an off the shelf hydraulic roller cam I figure I can use one to meet my goals as well. I have the 885 lifters already as I figured they would be needed. Do you think the limitations on the available springs will cause issues with controling the lifters or the valves? I have a rev kit on hand. That should help with lifter control if necessary. My limited understanding is that heavier springs are needed when you get stupid with the ramp on the cam for lifter control OR if you spin the fusk out of it and need more pressure to keep valves from floating. I do not plan on spinning the engine into oblivion but again my understaning is limited and I may learn that I have to. If I don't have to spin it like crazy I'll be content to use the rev kit to supplement spring pressure for lifter control and get a little crazy with the ramp up. I guess I was thinking that I could max out a non-'R' head with a hydraulic cam. I have no problem being wrong about that. If I end up going with a solid I will be pestering the shiznit out of our vendors to make a two piece valve cover for easy to do valve lash adjustments. Again thanks for your insight.

 

[Cme2fly]

Ditch the rev kit. Just use a good big block style valve spring. I have had good success running a PAC beehive spring on my mild(.540) solid roller setup. I drive my car on the street every chance I get and havn't had to adjust my valves since hot lashed. Pulling the valve covers should be the least of your worries. You are building a race engine right?

 

[Nasty Wendy]

Ditch the rev kit. Just use a good big block style valve spring. I have had good success running a PAC beehive spring on my mild(.540) solid roller setup. I drive my car on the street every chance I get and havn't had to adjust my valves since hot lashed. Pulling the valve covers should be the least of your worries. You are building a race engine right?

Car still has heat and AC. How much is 'every chance you get'? Twice a week? Three times a week? More? Would you drive it out of state? Would you drive it to New Orleans for Mardi Gras? I'm just trying to get a feel for how 'race' the car gets and how much 'street' I'd have to give up.

 

[Cme2fly]

I try to drive it at least 1 or 2 times weekly. My car still have AC and heat. I make a trip to Daytona with the car twice a year. (150 miles round trip) I would feel comfortable taking the car on a road trip, although the exhaust drone would drive me crazy. For some, the down side to a solid roller is the additional valvetrain noise. You can make a lot of power with a hydraulic roller. IMO, If you want to get all of the performance out of your combo stick a solid roller in it and ride. Look up 231dave, he has some of the best quality stage two parts I have seen including a few billet shafts.

 

[Nasty Wendy]

I'm going to be listening carefully to the valvetrain noise on the cars in Bowling Green. I'm pretty sure there will be a few cars there with solid cams. Thanks for the insight.

 

[turbofabricator]

"Wendy"........What E.T do you plan on running? Is your car licensed to run faster than 10.00? If not, then stick with a hydraulic roller 218/220 ish and drive it like you stole it. Dennis is running 10.05 @135 with a 218/220 hydrualic austemper cam, pump gas, alky, three mufflers (church-mouse quiet) AC, heat, cruise control, stock location PTE intercooler, TA heads, Champion intake. It will easily run in the 9's with Q16 fuel, but he chooses to keep it right where it runs. He will make a 9 second pass on pump gas and alcohol, some day with the right track (where they look the other way) Currently the StageII lost a spark plug and is being "fixed" so he is running a back-up 109 engine. (10.60's)
Cam choice is more a performance goal more than anything. If all-out is what you plan on running, then go all out on the cam. Solid roller, big springs, BIG RPM. What turbo and what converter is also a huge part of your decision. But you still have to start with intended goal, then work backwards. No other way to do it. SO............what ET/MPH are you targeting? The rest is fill in the blanks. (and someones bank account, too.)

 

[Nasty Wendy]

I spoke to Dan today. Me thinks he will be able to accomodate what I want with a hydraulic roller. Yippeeeee.

 

[blackgn1]

So whats the selection? Is it a secret?:biggrin:

 

[Nasty Wendy]

So whats the selection? Is it a secret?:biggrin:

I don't know. It'll be whatever he sends me. A billet something or another. ???? He took all my info and is putting something together for me. I don't know what it is yet.